I have a Dodge RAM 3500 diesel 2003 truck. I spent $600 trying to get this fixed to no avail. Dealer adjusted engine computer, and mechanic replaced intake manifold heater. Truck still won't start in the a. m. , even when outdoor temps. are 60-65 degrees, but it starts perfectly after one hour with the block heater plugged in. I contacted the Cummins diesel manufacturer and they say the truck should start at 40 degrees cold so they say the problem is not with the engine, but with something else in the truck. Any suggestions on what to check out next would be most appreciated.